Waveform covariance matrix design for robust signal-dependent interference suppression in colocated MIMO radars

In multiple-input multiple-output (MIMO) radars, interference can be properly suppressed by designing transmit waveforms. However, having an error in initial estimation of interferers' locations can result in degradation of signal-to-interference-plus-noise ratio (SINR), significantly. In this paper we consider the problem of robust interference suppression and SINR increment in collocated MIMO radars, in the presence of signal-dependent interference resources. We propose an efficient method to generate transmit waveform covariance matrix with the following properties: (a) robustness in interference suppression, (b) high SINR at the receiver, c) using the same power level for all transmit antennas and (d) suitable for generating BPSK waveforms in a closed-form. We solve the resulted optimization problems with numerical approaches in a short period of time. The proposed covariance matrix, by exploiting the correlated MIMO radar concept and a technique we use in the transmitter, yields to a better SINR level compared to conventional MIMO radars, phased array method and the recent introduced schemes. Simulation results validate our claims and show the advantages of our work .